In January, AMD launched their new quad-core Phenom II processors that were compatible with existing AM2+ motherboards and DDR2 memory. The new Phenom II processors were the first truly competitive AMD CPUs since Intel's introduction of the Core 2. The Phenom II 940 and 920, priced at $275 and $235, performed better than the equivalently priced Intel Q9400 and the Q8200. Now AMD has filled out the Phenom II line with five new models with integrated DDR3 and DDR2 support.

Intel responded quickly with Core 2 price cuts as we discussed, and AMD countered quickly with price adjustments that placed the Phenom II processors at price points where they compete very well with similarly priced Intel Core 2 processors. With the new Phenom II models just recently introduced, we now have a complete line of AMD Phenom II processors.

AMD Phenom Processors

Model

Clock Speed

HT Speed

L2 Cache

L3 Cache

TDP

Price

AMD Phenom II X4 940 BE

3.0GHz

1.8GHz

2MB

6MB

125W

$225

AMD Phenom II X4 920

2.8GHz

1.8GHz

2MB

6MB

125W

$195

AMD Phenom II X4 910

2.6GHz

2.0GHz

2MB

6MB

95W

OEM

AMD Phenom II X4 810

2.6GHz

2.0GHz

2MB

4MB

95W

$175

AMD Phenom II X4 805

2.5GHz

2.0GHz

2MB

4MB

95W

OEM

AMD Phenom II X3 720 BE

2.8GHz

2.0GHz

1.5MB

6MB

95W

$145

AMD Phenom II X3 710

2.6GHz

2.0GHz

1.5MB

6MB

95W

$125

AMD Phenom 9950

2.6GHz

2.0GHz

2MB

2MB

140W

$149

The new Phenom II processors are truly important introductions for AMD. In testing the new 45nm CPUs are competitive with the latest Intel Core II Quad (Penryn) processors. They are also the first AMD processors in over two years that can also compete with Intel processors in overclocking. In our own tests we were able to overclock to the 3.8GHz range with some Phenom II samples. The new Phenom II does exactly what AMD needs it to do to compete through the midrange.

The first Phenom II processors, the 940 and 920, feature a DDR2-only controller and an uncore bus of 1.8GHz. These two models will be phased out over time and replaced with the 945 and 925, which should begin shipping in April. The 945/925 will run a 2GHz uncore speed and will feature the dual DDR2/DDR3 controller used on the rest of the newest Phenom II processors. This will matter to some but it is a moot point from a performance perspective, since we have not found any real performance difference in DDR2 and DDR3 on Phenom IIs that support both memories.

Intel's latest Core i7 is still as much as 30% faster in some applications than the Core 2 Quad/Phenom II processors, so AMD did not reclaim the ultimate performance crown. However, Core i7 is at present a high-end CPU, with prices starting at $300 and extending to over $1000 just for the CPU.

With AMD competitive again through the midrange of the CPU space, it is time to take a closer look at putting together systems with the new Phenom II processors. With a broad CPU price range of around $120 to $230, there are quite a few choices in processors for a Phenom II system.

This Phenom II Buyers' Guide looks at three different builds that you might be considering. For builders who want a Phenom II system for as little money as possible we put together a Phenom II Entry system. The goal was simple - build a competent and balanced Phenom II system for as little money as possible.

Another typical buyer is attracted to the Phenom II because of the tremendous overclocking potential of the processor - something AMD fans have really missed for the last two years or so. As discussed in our overclocking analysis of the latest Phenom II, AnandTech reached 3.31GHz at stock voltage on the 2.8Ghz Phenom II 720 BE and 3.81GHz on the same CPU by increasing voltage and tweaking BIOS settings. That 36% overclock is something we often see with Intel Core 2 processors, but it is the best overclocking we have seen with an AMD CPU in a very long time.

Finally, there is the full-blown or performance Phenom II system. We hesitate to call this a High-End System, since the most expensive Phenom II is just $225. This is a very midrange CPU price. Our system components for the full-blown Phenom II are more upper midrange than high-end. That means we will not be pairing the Phenom II with a $1200 30" LCD monitor for 2560x1600 gaming. However, the CPU power is there if you aspire for more. You could definitely use a high-end graphics card and 30" monitor on a Phenom II 940 or 945 if you choose, and you would achieve superb performance.

With 4 dimm slots you would need 4GB dimms to populate the board with 16GB. The only 4GB dimms readily available are the Kingston 8GB DDR2-800 CAS6 kit in DDR2. They sell for over $400 for two dimms (8GB), or $800+ for 16GB.We're not opposed to more memory, but 16GB is really not very practical right now.

On the Overclocking systems generally the more memory slots filled the more limited the memory overclocking capabilities. Filling two slots with fast 2GB dimms (total 4GB) seemed the best formula for best overclocking potential. We didn't even consider 8GB (4x2GB) as an option for the OC systems. Since the Entry system is about price and value we also did not consider 8GB there. Reply

honestly, more than 4gb for home use is a waste. I have two rigs at home (one for me, the other for my girl). Mine is 4gb and her is 2gb. With dual-core cpu's and 4gb of memory you will never have a performance-wise problem on your computer. Of course you may always want the "better and fastest", but only a few percent of users are concerned about that. The vast majority only want to use some Word-app and read some emails.

Also, for these folks 32bit and 64bit OS are exactly the same things. With Windows Vista hard-coded limitation to only 4gb, there really is no need to go beyond 4gb. By the way, my OS is 32bits so I'm "loosing" 700mb to this artificial limit (and I will replace a hidden DLL soon to make it use the full 4gb). Reply

So true.
Had 6gbs on my machine for a while (had 2, then added 4 more), and as soon as I compared the performance delta between that and 4gbs, I ended up selling the old 2gbs so I now have just 4gbs. It is plenty for my usage pattern.

Also I don't get why the editor seems to implicate that a mid range CPU such as a phenom II will be mostly paired to pretty low end devices for anything.

I mean, come on, even if you're only an ocassional gamer, an IGP won't cut it. I don't see that even as well fitted enough for watching HD movies.

Only Vista 32-bit has a 4GB limitation; that's the whole point of 64-bit OSes. Of course, only 64-bit apps can access more than 3GB even on Vista 64-bit... perhaps that's what you meant? (I still curse Adobe on a regular basis for their lack of 64-bit applications!) Reply

Close. 32bit apps that are LargeAddressAware can hit up to 4GB under Vista x64.

This doesn't include the other benefits of more memory of course, such as additional applications being able to use their own chunk of memory without having to share with other memory-intensive applications. Reply